A consumer might elect to use a point-of-sale (POS) terminal and a payment card (e.g. credit card or debit card) to complete a financial transaction with a merchant (e.g. pay for a merchant's wares/services). After the consumer interfaces the payment card with the POS terminal, and the terminal reads the account number from the payment card, the POS terminal may generate an online authorization request (e.g. authorization amount, and account number), and transmit the authorization request to the merchant's financial institution (acquirer) via a secure acquirer network.
The acquirer initiates clearing of the transaction by transmitting the authorization request over a secure payment network to the issuer of the payment card. If the consumer's account with the card issuer has a credit or balance that is sufficient to complete the transaction, the card issuer posts the authorization amount to the consumer's account, generates an authorization response message, and transmits the authorization response message to the acquirer via the secure payment network. The acquirer returns the authorization response message to the POS terminal via the secure acquirer network.
The security requirements of the acquirer network and the payment network, together with the data traffic over those networks increases the latency of the online authorization/clearing process.